Psychometric Properties of the Adult Scale of Hostility and Aggression: Reactive/Proactive (A-SHARP) for Individuals with Intellectual Disabilities

Abstract

Background: The Adult Scale of Hostility and Aggression: Reactive/Proactive (A-SHARP; Matlock & Aman, 2011) was developed to assess aggressive problem behaviors common in adults with intellectual and developmental disabilities. The 52-item A-SHARP has five subscales (Verbal Aggression, Physical Aggression, Hostile Affect, Covert Aggression, and Bullying) and in addition provides a score on the degree of provocation of the exhibited aggression. Psychometric properties as reported by Matlock and Aman (2014) were very good, yet need to be corroborated. Method: In 2013, staff at a day treatment program for adults with intellectual disabilities completed ratings on the A-SHARP for all their clients (n=194) and the Behavior Problems Inventory-01 (BPI-01; Rojahn et al., 2001). The BPI-01 was also completed in 2008. The Behavior Problems Inventory-Short Form (BPI-S; Rojahn et al., 2012a) was completed in 2012. Results: Internal consistency was excellent for the A-SHARP Problem and Provocation scales (Cronbach α =.96 and .90), ranging from .76 to .93 for the five subscales. As for concurrent validity of the A-SHARP, subscale scores correlated with the 2013 BPI-01 Aggressive/Destructive Behavior frequency and severity ratings from .15 to .68 (Spearman ρ). Furthermore, regression analyses suggest that scores from the 2008 BPI-01 and the 2012 BPI-S predicted scores on the relevant A-SHARP scales. Conclusions: The A-SHARP was found to have acceptable to excellent internal consistency, while evidence for concurrent validity of select A-SHARP subscales was moderate. These findings and their implications for the assessment of aggressive behavior in adults with intellectual and developmental disabilities are discussed.